I have been trying to track down a suspension or drivetrain issue in WJ 4.7 2"BB for a couple of weeks now. I've replaced the axle shaft, bearing hub assembly and this past weekend I have been working on replacing the ball joints in the passenger front wheel.

After I finally removed the old ball joints, and managed to squeeze the new ones in, I got the lower ball joint to line up well with the knuckle and was able to get it to where it should be. The upper ball joint is a different story. I cannot really get the knuckle to line up right at top. As I attempt to tighten up the nut, the bolt inside the ball joint turns too. Not always though, it just seems that there is enough pressure that it ends up moving which I find very odd to begin with. Why isn't it staying and allowing me to tighten up the nut? What can I do? Is the new upper ball joint defective? Why won't the knuckle line up as it did before? Is there a particular procedure for this? I was so close to being done and I am pretty confident that the ball joints were the issue. I really want to get my Jeep back on the road and home so I can do more work on it.
Your feedback is greatly appreciated!

I have found this issue when using cheap ball joints that have a polymer (plastic) bearing surface. Usually I can get them to seat enough to stop the turning using a hammer (not on the stud but the upper control arm) and gently turning the nut until you have enough torque to hold it in place. However, if I were in your place I would first find out what kind of bearing surface your joints have and if they are polymer I would return them as defective. If I am not putting dealer parts back in I usually use the NAPA premium line. They have metal bearing surfaces and you can feel the difference in the movement of them. I have yet the need to replace the metal surface joints, unlike the 6 months to 2 years I use to get with the others.

Thanks for your reply Ben. The ball joints I am using are Napa Premium. I think my issue mostly lies with the knuckle not lining up right to begin with. I am wondering if I should dissassemble the tie rod and drag link ends so that the knuckle is completely free? I can then just try to bolt it on without having interference. I have read many posts on forums for all kinds of cars that this turning of the bolt in the ball joint is quite common, so I am thinking that it is the pressure I am applying to try and get the knucle to fit better into place that is causing the bolt to turn and the pressure downward is too great.

Got the knuckle off. Reseated it and it still won't go beyond a certain point on the top ball joint. Something in the bottom joint is keeping it from going any further. I have the right parts (Napa Premium Upper: 260-1291, Napa Premium Lower:260-1554). I can insert the knuckle into the top joint to where it is supposed to be if I don;t put the lower through as well.

What am I doing wrong?

I noticed on the top ball joint that I could push the bolt up into the casing, is that the case with the lower one as well and I am supposed to do that? If that is the case, I can imagine that this would solve the issue but before I go trying to push the bolt inward, I would rather know from those of you with experience.

I have a couple of hours left at the office and I really need to get this thing out of here.

Just to double check... Looking at the description for the ball joints at NAPAonline; the upper balljoint does not articulate but only spins and the lower is a standard ball joint. You installed them in the correct locations and didn't switch them right? I am not sure what else could be your problem...

I finally managed to get it on, still has a gap that i am not happy with. Either way, my original issue still persists. Still get clunking/soft grinding/vibrations from the right front area when turning the wheel left and while going over bumps. Have replaced the axle shaft, hub bearing assembly and rhe ball joints on the right front wheel. Brakes are brand new( calipers, rotors, pads). Next up, steering stabalizer and tie rod ends unless someone can give me some mire advice/troubleshooting tips...